1. Field of the Invention
This invention relates to a sample-conveying system having a belt-conveyor type conveying mechanism for conveying a holder that holds a receptacle, such as a test tube, which contains blood to be tested.
2. Description of the Related Art
Generally, in a sample-conveying system having a belt conveyor, long conveying paths of complicated forms are arranged substantially throughout the installation space of the system, depending on the purpose of use. Many long conveying paths may block passages for operators and work vehicles. If samples must be moved over a long distance, moreover, long conveying paths sometimes may be arranged for conveyance only, although the samples are not processed in the middle of the conveying paths.
Sample-conveying systems using mobile units have been proposed to solve this problem. One such system is described in Jpn. Pat. Appln. KOKAI Publication No. 2002-137822. The conventional sample-conveying system using a mobile unit includes a belt-conveyor type conveying mechanism having first and second conveying paths that are separated from each other. This conveying mechanism has holders for holding receptacles that contain samples. To convey these holders, the mobile unit moves between a conveyance terminal end portion of the first conveying path and a conveyance starting end portion of the second conveying path. The mobile unit is guided by a guide member as it runs.
The mobile unit that is used in the conventional sample-conveying system described above has a conveying lane on its upper surface. The conveying lane is connected alternatively to respective conveying lanes of the first and second conveying paths. One or several holders that hold the receptacles are delivered at a time from the conveyance terminal end portion of the first conveying path to the conveying lane of the mobile unit. These holders are conveyed to the second conveying path by the mobile unit. Then, they are delivered from the conveying lane of the mobile unit to the conveyance starting end portion of the second conveying path. In order to feed many holders from the first conveying path to the second conveying path by the sample-conveying system, the mobile unit must frequently move between the first and second conveying paths. If the space between the first and second conveying paths is utilized as a passage for an operator or work vehicle, in the conventional sample-conveying system of this type, the mobile unit causes danger as it passes through the passage frequently.